title: Deoxyadenosine bisphosphate derivatives as potent antagonists at P2Y1 receptors.
abstract: Adenosine 3',5'- and 2',5'-bisphosphates previously were demonstrated to act as competitive antagonists at the P2Y1 receptor (Boyer et al. Mol. Pharmacol. 1996, 50, 1323-1329). 2'- and 3'-Deoxyadenosine bisphosphate analogues containing various structural modifications at the 2- and 6-positions of the adenine ring, on the ribose moiety, and on the phosphate groups have been synthesized with the goal of developing more potent and selective P2Y1 antagonists. Single-step phosphorylation reactions of adenosine nucleoside precursors were carried out. The activity of each analogue at P2Y1 receptors was determined by measuring its capacity to stimulate phospholipase C in turkey erythrocyte membranes (agonist effect) and to inhibit phospholipase C stimulation elicited by 10 nM 2-MeSATP (antagonist effect). Both 2'- and 3'-deoxy modifications were well tolerated. The N6-methyl modification both enhanced antagonistic potency (IC50 330 nM) of 2'-deoxyadenosine 3',5'-bisphosphate by 17-fold and eliminated residual agonist properties observed with the lead compounds. The N6-ethyl modification provided intermediate potency as an antagonist, while the N6-propyl group completely abolished both agonist and antagonist properties. 2-Methylthio and 2-chloro analogues were partial agonists of intermediate potency. A 2'-methoxy group provided intermediate potency as an antagonist while enhancing agonist activity. An N1-methyl analogue was a weak antagonist with no agonist activity. An 8-bromo substitution and replacement of the N6-amino group with methylthio, chloro, or hydroxy groups greatly reduced the ability to interact with P2Y1 receptors. Benzoylation or dimethylation of the N6-amino group also abolished or greatly diminished the antagonist activity. In summary, our results further define the structure-activity of adenosine bisphosphates as P2Y1 receptor antagonists and have led to the identification of the most potent antagonist reported to date for this receptor.
authors.affiliation: Molecular Recognition Section, National Institute of Diabetes, Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland 20892-0810, USA.
authors.forename: E
authors.initials: E
authors.lastname: Camaioni
authors.forename: J L
authors.initials: JL
authors.lastname: Boyer
authors.forename: A
authors.initials: A
authors.lastname: Mohanram
authors.forename: T K
authors.initials: TK
authors.lastname: Harden
authors.forename: K A
authors.initials: KA
authors.lastname: Jacobson
mesh_terms: D000818:Animals; D002851:Chromatography, High Pressure Liquid; D003838:Deoxyadenine Nucleotides / Q000737:chemistry* / Q000494:pharmacology*; D004910:Erythrocyte Membrane / Q000187:drug effects / Q000378:metabolism; D008956:Models, Chemical; D058919:Purinergic P2 Receptor Antagonists; D058472:Receptors, Purinergic P2Y1; D013329:Structure-Activity Relationship; D014422:Turkeys; D010738:Type C Phospholipases / Q000378:metabolism
chemical_list: D003838:Deoxyadenine Nucleotides; D058919:Purinergic P2 Receptor Antagonists; D058472:Receptors, Purinergic P2Y1; C018891:deoxyadenosine diphosphate; D010738:Type C Phospholipases